1. Field of the Invention
The present invention relates to a waste-toner housing device for use in an image forming apparatus, and an image forming apparatus.
2. Description of the Related Art
In conventional image forming apparatuses such as copiers, facsimile machines, and printers, a service staff generally carries out replacement of consumable or life-limited components and maintenance of them. However, the trend is changing and the user is carrying out exchange of supplies and maintenance. In addition, smaller components are used for suppressing the size and the cost of the image forming apparatus. Therefore, the user needs to periodically exchange parts that deteriorate in quality earlier than the life of the apparatus or a waste-toner container. The waste-toner container contains residual materials such as toner, which is a developer, or fiber from transfer sheets. Moreover, because the image forming apparatus is installed adjacent to a user of a personal computer in the times of widespread use of personal computers reduction of noise during operation of the image forming apparatus is another problem that needs attention.
Toner that fails to be transferred onto the transfer sheet is removed and conveyed into a waste-toner container. To recycle the waste toner, an additional path and an additional driving unit for collecting the waste toner becomes necessary. As a result, the image forming apparatus becomes larger. The waste toner contains foreign materials such as fiber from the transfer sheets. Removal of the fiber makes control process or reuse process complicated. If a full-color image forming apparatus that uses three or four toners performs the waste-toner recycling process, considerably larger waste-toner container is required so that structure of the full-color image forming apparatus becomes much complicated. For this reason, in some of the image forming apparatuses, the waste toner is just conveyed into the waste-toner container and the waste-toner container is replaced with another one when the waste-toner container is full with the waste toner.
It is possible to provide a waste-toner container that can contain all the waste toner generated during a whole life of the apparatus. However, such a waste-toner container is considerably large. Therefore, there is a need for filling the waste toner into the waste-toner container in an effective manner to decrease the frequency of replacing the waste-toner container. The waste toner is poured into the waste-toner container from the top, and a sensor is installed on the top part of the waste-toner container. The sensor is a detecting unit for detecting whether the waste-toner container is filled to its capacity and for notifying time of exchange. Exchange cycle of the waste-toner container is prolonged if the waste-toner container is filled with the waste toner without an unfilled space, that is, the waste toner does not accumulate in one particular part of the waste-toner container.
In the conventional image forming apparatus two methods are used to properly fill up the waste-toner container. One method is to periodically shake the waste-toner container and the other method is to locate an agitating screw on the top part of the waste-toner container to flatten a pile of the waste toner inside the waste-toner container.
Japanese Patent Application Laid-Open No. H11-258962 discloses an image forming apparatus in which waste toner removed by the cleaning device is mixed with fresh toner supplied to a developing device, and mixed toner is conveyed to an agitating unit. An accumulating unit is formed in front of the mixing unit in the image forming apparatus. In the image forming apparatus the fresh toner is fed to the accumulating unit and the waste toner is returned to the accumulating unit. Japanese Patent Application Laid-Open No. 2004-102137 discloses an image forming apparatus that includes a waste-toner housing device that is shaped able to fit into a spare space in a main body of the image forming apparatus. The waste-toner housing device includes a waste container and a conveying member that conveys collected waste toner within the waste-toner container.
However, in the conventional image forming apparatus, collected waste toner is piled up in one part of the waste-toner container, and space in the waste-toner container is not effectively filled.